1. Field of the Invention
The present invention relates to vehicle guidance methods, and more particularly to a correlated velocity guidance method for steering a solid propellant ballistic vehicle during powered flight which eliminates the requirement for cutoff control in the booster stages.
2. Description of Prior Art
Cutoff control or thrust termination of liquid fueled vehicle boosters is relatively easy due to the ability to shut off the flow of the propellants using valves. However, thrust termination of solid fueled vehicle boosters is relatively complex since additional hardware is required which adds weight and complexity, i.e., reduces payload and/or range, increases cost and increases probability of failure. Even if each booster could be selectively loaded for each range desired, which is impractical, inflexible and more costly, the burn rate fluctuations from a nominal value would still result in an error at booster burnout without cutoff control. Therefore, a method for achieving booster burnout at the desired position and velocity regardless of range without additional hardware for cutoff control is desired.